P0A0D: interlock feedback is high under one of two source states

P0A0D in the cited GM hybrid summary is a high-feedback interlock diagnosis. It evaluates two cases: the source is inactive and the sensed fraction remains too high, or the source is active and the sensed fraction exceeds that state's separate upper limit.

One voltage limit cannot describe both cases

The published thresholds differ between the sourced and unsourced states. A technician who records only the sensed reading, without the source command, cannot identify which comparison produced the fault.

The source also gives different failed-sample counts for those two branches. The complete monitor therefore includes command state, signal level and persistence; it is not simply an instantaneous “voltage present” check.

High feedback is not high-voltage bus measurement

The interlock sensing circuit uses a low-voltage reference in this table. Its diagnostic result does not measure traction-battery terminal voltage and does not certify that opening a connector is safe. The high-voltage isolation and verification procedure remains separate.

The row requires adequate 12-volt supply and identifies a one-trip reporting classification. Preserve any supporting supply faults and the controller that reported the interlock result.

This summary supplies no connector locations or approved bypass procedure. A qualified technician should use the vehicle-specific interlock diagnosis to determine where the sensed state diverges from the command. Defeating the interlock would conceal the very condition being monitored and cannot serve as repair verification.

Application limits

Document-level 2015 GM diagnostic table; per-code vehicle/engine/calibration applicability not established.

Source

15OBDG01 Hybrid Diagnostics, physical PDF pages 553.